Inside Man - (Head Cases) by John McMahon (Hardcover)

About the Book

"FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI's hidden edge, brought in for cases that no one else can solve. PAR's latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him. As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man's picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.? As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?"--Provided by publisher.

Book Synopsis

In this sequel to McMahon's electrifying series debut, Head Cases, Gardner Camden and the PAR team return to investigate potentially connected cases.

FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI's hidden edge, brought in for cases that no one else can solve.

PAR's latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.

As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man's picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?

As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?

Review Quotes

Praise for Inside Man:
"Suspenseful... [an] intriguing series... McMahon confidently combines the cerebral with solid action, skimping on neither aspect."-- Oline Cogdill, South Florida Sun Sentinel

"Gardner Camden is one of the freshest new characters to hit the thriller scene . . . The tough puzzles that PAR is called in to handle make for entertaining, mind-bending reading. They aren't simple whodunits. These books really make you think. Inside Man presents a plot that is as unique as its protagonist. And it comes off beautifully. John McMahon, please keep satisfying readers with Head Cases novels for a long time."--Bookreporter

"McMahon has the literary courage to take his tale in a whole different direction, even after it raced out of the box. That's the stuff of a very confident storyteller who knows how to take us in his grasp and not let go. Inside Man is not to be missed."--BookTrib

"The second book is just as good as the first . . . Both Head Cases and Inside Man achieve a rare balance of fast pace and thoughtful, even luminous quieter moments. A tip: Don't rush to finish Inside Man when you should be sleeping. The big finish is so tense and thrilling, you'll be up all night."--St. Louis Post-Dispatch

"The plot is twisty... A slick and lively thriller featuring a team you'll want to hang with."--Kirkus Reviews

"In the absorbing follow-up to Head Cases (2025), the brilliant and neurodivergent Camden once again looks outside the box to deliver results. A fascinating protagonist, he can make readers laugh or sigh and is as compelling as his newest case."--Booklist

Praise for Head Cases:
"Mr. McMahon's inventive, eventful, smartly written Head Cases, with its brilliant but fallible protagonist, its twisted-minded perpetrator, and its mix of sentiment and intrigue, is a terrific debut that augurs well for further installments in the series." -The Wall Street Journal

"A stellar new series...Head Cases balances fully fleshed-out, quirky characters with McMahon's fine eye for details about the inner workings of investigations coupled with methodical plotting...McMahon's precise storytelling in Head Cases should assure many adventures with this intelligent team."--Oline Cogdill, South Florida Sun Sentinel

"In this suspenseful cat and mouse thriller, Camden balances brilliance with a deeply flawed awareness of social cues, retaining the edge of a compelling protagonist. This, combined with McMahon's gripping plot, will pull readers in."--Booklist

"McMahon introduces several clever wrinkles to this classic cat-and-mouse setup, while making the socially awkward Camden and his colleagues three-dimensional enough to sustain future installments. With pulse-pounding action and enough surprises to blindside even seasoned mystery fans, this is an excellent start." -Publishers Weekly (Starred review)

"A superior cat-and-mouser, with both parties armed to the teeth."-Kirkus Reviews

"A must for your TBR pile."--FirstClue

"A twisting FBI procedural with a cool cast of characters... I was in heaven... Not only because there's more than one serial killer, but I also loved that the PAR agents don't play well with others." -Minnesota Star Tribune

"Fast paced... a thrilling conclusion... gives good reason to get attached to the characters..." -St. Louis Post Dispatch

"Both meticulously plotted and populated by offbeat characters, Head Cases is a series debut that readers will be talking about all year long...Gardner Camden is sure to become a fan favorite... As this is the launch of a series, watching his evolution--not just as an FBI agent, but as a human being--will be the reason readers return for case after case."--BOLO Books

"Head Cases begins as a riveting story about the hunt for an apex predator--a killer of serial killers--but quickly becomes so much more: the only road back to what's left of one man's family, friendships, and identity. It's a taut, thrilling read." --Jess Lourey, Edgar-nominated author of The Taken Ones

"Grabbed me from page one!" - J.A. Jance

"John McMahon's Head Cases is everything this crime fiction-lover could want: gripping, twisty, and atmospheric, with a harrowing and intriguing plot, gorgeous prose, and fresh and compelling characters. McMahon doesn't just knock the ball out of the park with this one--he sends it flying into the next universe. I sincerely hope this is the beginning of a new series because I want more!" - Karen Dionne, author of the #1 international bestseller The Marsh King's Daughter and The Wicked Sister

"I couldn't get enough of this addictive, propulsive story of intellect and intrigue. Head Cases is a masterfully-done game of cat and mouse with an unforgettable cast of characters." --Matthew Quirk, New York Times bestselling author of The Night Agent

About the Author

JOHN McMAHON'S debut novel The Good Detective was labeled "pretty much perfect" by the New York Times, which listed it among their "Top Ten Crime Novels of 2019." The book was also a finalist for the 2020 Edgar Award and the ITW Thriller Award, both for Best First Novel. Head Cases is his fourth novel, and is currently in development with Warner Bros TV for a streaming series on HBO Max. John currently lives in Southern California with his wife, two kids, and a rescue dog. He splits his time between crime-writing and his day job in advertising.